add type to bucket

src/cache.erl

@@ -90,6 +90,7 @@ start() ->
 
 %%
 %% start new cache bucket, accepted options:
+%%    {type,   set | ordered_set} - cache segment type (default set)
 %%    {policy, lru | mru} - cache eviction policy
 %%    {memory, integer()} - cache memory quota in bytes
 %%    {size,   integer()} - cache cardinality quota

src/cache.hrl

@@ -30,6 +30,7 @@
 -define(DEF_CACHE_POLICY, lru).
 
 %% default cache ttl and number of generations
+-define(DEF_CACHE_TYPE,  set).
 -define(DEF_CACHE_TTL,   600).
 -define(DEF_CACHE_N,      10).
 

src/cache_bucket.erl

@@ -36,7 +36,8 @@
    name   = undefined  :: atom(),     %% name of cache bucket
    heap   = []         :: list(),     %% cache heap segments
 
-   n      = ?DEF_CACHE_N      :: integer(),  %% number of segments          
+   n      = ?DEF_CACHE_N      :: integer(),  %% number of segments
+   type   = ?DEF_CACHE_TYPE   :: atom(),          
    ttl    = ?DEF_CACHE_TTL    :: integer(),  %% cache time to live
    policy = ?DEF_CACHE_POLICY :: integer(),  %% eviction policy
 
@@ -73,6 +74,9 @@ start_link(Name, Opts) ->
 init([Name, Opts]) ->
    {ok, init(Opts, #cache{name=Name})}.
 
+init([{type, X} | T], #cache{}=S) ->
+   init(T, S#cache{type=X});
+
 init([{policy, X} | T], #cache{}=S) ->
    init(T, S#cache{policy=X});
 
@@ -525,7 +529,7 @@ heap_has(_Key, []) ->
 %%
 %% init cache heap
 init_heap(#cache{}=S) ->
-   Id = ets:new(undefined, [set, protected]),
+   Id = ets:new(undefined, [S#cache.type, protected]),
    ?DEBUG("cache ~p: init heap ~p~n", [S#cache.name, Id]),
    Heap = #heap{
       id          = Id,